6.33. Customize Default iPXE Boot Setting

A compute server’s BIOS can be set to always PXE network boot using the BIOS boot order. The default RackHD response when no workflow is operating is to do nothing - normally falling through to the next item in the BIOS boot order. RackHD can also be configured with a default iPXE script to provide boot instructions when no workflow is operational against the node.

6.33.1. Default iPXE Boot Customized OS Into RAM

To configure RackHD to provide a custom iPXE response to a node outside of a workflow running, such as booting a customized kernel and initrd, you can do so by providing configuration to the Node resource in RackHD. This functionality can be enabled by using a PATCH REST API call adding bootSettings to a node.

curl -X PATCH \
    -H 'Content-Type: application/json' \
    -d @boot.json \

A example of boot.json:

            "bootargs":"console=tty0 console=ttyS0,115200n8"

For bootSettings, profile and options are MUST required:

Name Type Flags Description
profile String required Profile that will be rendered by RackHD and used by iPXE
options Object required Options in JSON format used to render variables in profile

A default iPXE profile defaultboot.ipxe is provided by RackHD, and its options includes url, kernel, initrd, bootargs

Name Type Flags Description
url String required Location Link of kernel and initrd, it could be accessed by http in node, the http service is located in RackHD server or an external server which could be accessed by http proxy or after setting NAT in RackHD. In RackHD server, the root location could be set by httpStaticRoot in config.json or in SKU Pack’s config.json
kernel String required Kernel to boot
initrd String required Init ramdisk to boot with kernel
bootargs String required Boot arguments of kernel

6.33.2. Customize iPXE Boot Profile

profile in bootSettings could be customized instead of defaultboot.ipxe. defaultboot.ipxe is provided by default, and its options url, kernel, initrd, bootargs are aligned with the variables <%=url%> <%=kernel%> <%=initrd%> <%=bootargs%> in defaultboot.ipxe, so if the profile is customized, the options also should be aligned with the variables that will be rendered in customized iPXE profile just like defaultboot.ipxe


kernel <%=url%>/<%=kernel%>
initrd <%=url%>/<%=initrd%>
imgargs <%=kernel%> <%=bootargs%>
boot || prompt --key 0x197e --timeout 2000 Press F12 to investigate || exit shell